Performance of a hydrophobic heat and moisture exchanger at different ambient temperatures

Intensive Care Med. 1993;19(6):351-2. doi: 10.1007/BF01694711.


Objective: To evaluate the effect of different room temperatures on hydrophobic heat and moisture exchangers (HME) humidifying capability and efficiency.

Methods: Stock HMEs were tested in vitro using an already described test model, with separation of inspiratory and expiratory gas. Absolute humidity (AH) was measured by means of dry-wet dual thermocouple, and HME efficiency was computed as the ratio between expired to inspired AH, at room temperature of 20 and 26 degrees C.

Results: Inspired gas temperature and AH were significantly higher at 26 than at 20 degrees C; since expired AH remained substantially unchanged, HME efficiency was also higher in warmer environment.

Conclusions: Hydrophobic HMEs appear to be affected by room temperature, increasing their humidifying ability and their efficiency with its rise.

Publication types

  • Comparative Study

MeSH terms

  • Cold Temperature
  • Evaluation Studies as Topic
  • Filtration / instrumentation
  • Hot Temperature
  • Humidity
  • Respiration, Artificial / instrumentation*
  • Temperature*
  • Time Factors